Buffing method and apparatus



Jan. 25, 193 8. STEVENS 2,106,442

BUFFING METHOD AND APPARATUS,

Filed April 24, 1935 6 Sheets-Sheet ll INVENTOR Horace D. Sreuens ATTORNEY H. /D. STEVENS BUFFING METHOD AND APPARATUS Filed April 24, 1935 6 Sheets-Sheet 2 INVENTOR Horace T). Stevens ATTORNEY Jan. 25, 1938. H. o. STEVENS BUFFING METHOD AND APPARATUS e Shets-Sheet s Filed April 24, 1955 NM m Q lNVENTO Horace D. Siemens ATT%NEY Ill/{11145 Jan. 25, 1938. H STEVENS 2,106,442

BUFFING METHOD AND APPARATUS Filed Abril 24, 1935 6 Sheets-Sheet 5 8 I INVENTOR Horace D. Stevens ATTORNEY Jan. 25, 1938. H. D. STEVENS BUFFING METHOD AND APPARATUS 6 t e e h 4 S t e m s 6 Filed April 24, 1935 INVENTOR Y E s m w m m A .0 T D e c m 0 H Patented Jan. 25, 1938 UNITED STATES PATENT OFFICE Firestone Tire & Rubber Company,

Akron,

Ohio, a corporation of Ohio Application April 24, 1935, Serial No. 17,940

13 Claims.

This invention relates to bufling methods and apparatus, and more especially it relates to procedure and apparatus for bufiing or abrading both sides of the rubber flanges or bases formed integrally upon rubber valve stems such as are used for inflatable rubber articles, for example, inner tubes.

In valve stems of the character mentioned, the base flanges may be of elliptical or rhombus shape in plan, the latter form only being illustrated in the accompanying drawings. Said base flanges also are formed with feather edges, so that the buffing thereof must proceed toward said edges or margins from a point within the same to avoid lifting and scuffing of the thin marginal portions.

The chief objects of the invention are to provide an improved method and improved apparatus for the bufiing of rubber valve stem base flanges.

More specifically the invention aims to provide,

in a single machine, the means for bufiing both sides of said base flanges. Further objects include continuous operation; automatic means for presenting different portions of the work to the abrading mechanism; automatic delivery of the finished work from the machine; and the saving of time and labor. Other objects will be manifest.

Of the accompanying drawings:

Figure 1 is a plan view of apparatus embodying and adapted to carry out the invention, in its preferred form, and the work therein;

Figure 2 is a front elevation thereof;

Figure 3 is a detail plan view, on a larger scale,

of a portion of the mechanism shown in Figure 1, showing how the work is turned axially through an angle of 90 in one region of its orbit;

Figure 4 is a section on the line l-4 of Figure 3;

Figure 5 is a section on the line 5-5 of Figure 4;

Figure 6 is a full size fragmentary elevation showing the top face of the work being buffed in the direction of its long axis, a part of the work- 5 supporting structure being shown in section;

Figure 7 is a section on the line 1-1 of Figure 1, on a larger scale, showing how one end portion of the bottom face of the work is buffed.

Figure 8 is a section on the line 8-8 of Figure '7;

Figure 9 is a detail plan view of a portion of the mechanism shown in Figure 1, on a larger scale, showing how the work is turned axially through an angle of 180;

Figure 10 is a detail plan view of the apparatus adjacent the work-delivery station, showing how the work is turned through an angle of preparatory to its ejection from the machine; and

Figure 11 is a plan view of a modified form of work-holding device that supports a different .5, form of valve stem with its bottom face uppermost.

The improved methodand apparatus may be described briefly as follows: The work, consisting of rubber valve stems, is manually mounted upon a constantly moving carrier having orbital movement that carries the work past a plurality of stations whereat the top face of the work is buffed. At one of said stations the work is turned through an angle of 90 so as to present a different portion of its surface to the buffing mechanism. Coming back to point-of starting, indicated by the letter A in Figure 1 of the drawings, the work is manually removed from its initial position on the carrier and replaced thereon in 20 a different position. In its new position it is carried past a plurality of stations where its bottom face (disposed uppermost) is buffed. Between said last mentioned stations the work is turned angularly through so as to present a different 25 portion of its surface to the succeeding buffing mechanism. Again approaching the point of starting, the work is automatically ejected from the machine and received in a suitable receptacle.

Referring to the drawings, 15 is a base plate, l 6, it are a plurality of legs rising therefrom, and H is a top plate supported by said legs somewhat above said base plate. Concentrically mounted over a suitable aperture (not shown) in the top plate I7 is a bearing bracket l8 that carries an 35 upwardly extending spindle l9. Journaled upon the latter and resting upon a suitable thrust bearing 20, Figure 1, on the top of bracket I8 is a large gear 2!, and secured to the top face of the said gear is a turret 22. A collar 23 on the upper 40 end of spindle l9 retains the gear 2| and turret 22 in place thereon.

The gear 2| is driven by a pinion 25, Figure 1, that is meshed therewith, said pinion being mounted upon the upper end of a vertical pinion 45 shaft 26 that is journaled in a suitable bearing bracket 2'! upon top plate ll, said pinion shaft extending downwardly through said top plate and having its lower end connected, by means of coupling 28, to the upper end of a driven shaft 50 29 of a reduction gear device 30. The latter is mounted upon base plate I5, and is driven by means of a pair of transmission belts 3|, 3| from the shaft 32 of an electric motor 33 that also is mounted upon base plate !5. The motor 33 is 55 constantly driven during the operation of the apparatus, and serves to rotate the turret 22 in the direction indicated by the arrow in Figure 1.

The turret 22 comprises a plurality of radial work-supporting arms 35, 35 (herein shown as ten in number), which arms substantially overhang the outer periphery of said turret. The overhanging portion of each arm 35 is provided with two work-seating portions for respective work units, such as the rubber valve stems 36 best shown in Figures 3 and 8, the outermost workseat being arranged to support the work on a horizontal axis, on the leading lateral edge of the arm, and the inner work-seat being arranged to support the work on a vertical axis, in inverted position with the bottom face of its base flange, designated 36a, disposed upwardly. The work makes its first passage through the machine, as previously explained, while mounted upon the outermost work-seats of the turret, which workseats will now be described, attention being directed especially to Figures 3 to 6 of the drawings.

Mounted upon the leading edge of each arm 35, at the outer end thereof, is a saddle-like worksupport 33 that has a rounded nose or leading edge and is substantially narrower than the short axis of the base flange 35a of the work. Projecting from the nose or leading edge of Work-support 38 is a spindle 39 upon which the work is mounted by engagement of the spindle in the axial bore 36b of the work, said spindle having tapered, square outer end portions adapted to engage in the metal insert 360 of the work, and having a short, cylindrical shoulder 46 at its base adapted to fit within the bore 361) of the work with a force fit, whereby the work is frictionally retained on said spindle. The spindle 39 is carried by a generally cylindrical spindle holder 4] that is journaled in a similarly shaped bore 42 in the work-support 38 and arm 35, the rear end of said bore intersecting a slot 43 in the top face of the arm 35 beneath the support 38, said slot extending longitudinally of the arm from the outer end thereof. Slidably mounted in slot 43 is a cam arm 44 that has a cam roller 45 journaled on a vertical axis in its outer end. There is a compression spring 46 in slot 43 between the inner end of cam arm 44 and the inner end of said slot, said spring normally urging the cam arm outwardly. The inner end of spindle holder 4! carries an eccentrically disposed stud or pin 41 that extends into a transverse slot 48 in the cam arm 44, the depth of the latter and the eccentricity of the stud being such that the stud limits the reciprocating movement of the cam arm 44 in both directions, and reciprocation of said arm turns the spindle holder 4!, spindle 39, and work 36 thereon through an angle of exactly degrees. This is best shown in Figure 4 where the alternative positions of the cam arm 44 and the valve stem flange 35a are shown in full and in broken lines.

Reciprocation of the cam arm is effected by means of an elongate cam 55 that is carried upon a pair of brackets 5|, 5| mounted upon top plate 11. The cam 50 extends into the orbit of the cam roller 45 in a region that is about threequarters of a revolution of the turret beyond the work-loading station A, said cam being associated with work-buffing mechanism presently to be described.

The work is manually mounted upon the worksupporting spindle 39 at station A with the long axis of its base flange disposed vertically, as shown in full lines in Figure 4, and is subjected to the first bufiing operation after moving about 90 in its orbit, in which operation the leading face of base flange 36a is buffed in the direction of its long axis, from a region adjacent the stem to opposite extremities of said flange, as is most clearly shown in Figure 6. The bufling is efiected by means of a pair of brushes 53, 54 preferably provided with wire bristles, which brushes are disposed one above the other in a vertical plane, and rotated in opposite directions. The brushes 53, 54 are spaced apart from each other a sufficient distance to permit the work supports 38 to pass therebetween with a slight flexing of the brush bristles, the brushes moving in opposition to the movement of the said work supports. The arrangement is such that when a valve stem 36 on a supporting spindle 39 is carried between the brushes 53, 54, the base flange 36a of the valve stem is flexed rearwardly onto the work support 38, the latter providing a rigid backing for opposite end portions of the said base flange as the brushes buff the same, toward their terminal portions.

The bufiing brushes 53, 54 are mounted upon the adjacent ends of respective parallel, horizontal shafts 55, 56 that are journaled in pairs of bearing brackets 51, 51 and 58, 58 mounted upon respective vertically adjustable slides 59, 60 that are carried by an upright bracket BI on the top plate l'l. Adjusting screws 62 are provided for adjusting the positions of slides 59, 60 to compensate for wear on brushes 53, 54. The other ends of shafts 55, 56 carry respective driven pulleys 63, 54 about which is trained a driving belt 65, the belt also passing about a driving pulley 66 on the shaft of motor 33, and about an adjustable 1 idler pulley 61 carried by the bracket 6|. The belt passes about pulleys 63, 64 in the proper manner to drive them in opposite directions,

The buffing of the top (leading) face of the base flange 36a of the work in the direction of its short axis is effected at a point in the orbit of the work that is removed from the point where the buffing along the long axis thereof is accomplished. During this second bufiing operation the cam roller 45 is in engagement with the cam 50 previously described whereby the cam arm 44 is pressed inwardly of the arm 35, with the result that the work is turned axially 90 from its normal position and the short aXis of its base flange is disposed vertically. The bufiing apparatus employed in this second bufiing operation is substantially identical with that employed for the previously described operation, like parts being indicated on the drawings by the same numerals with the exponent a. The second buffing apparatus is driven by a motor 69 that is somewhat smaller than motor 33 because it is not required to drive turret 22. The Work resumes its normal position with relation to its work support as soon as the cam roller 45 passes out of engagement with cam 50.

The innermost work seats wherein the work is supported during its second passage through the apparatus are located on the respective arms 35 somewhat radially inwardly of the Work seats previously described. The inner work seats are identical so that a description of one will suifice for all, attention being directed especially to Figures 7, 8 and 11.

Mounted upon the radial arm 35 is a rectangular holder II that projects laterally each side of said arm, said holder being tapered so that its top face slopes downwardly toward its leading end. The holder H is formed with a centrally disposed bore 12, and in its top face is formed with a relatively large counterbore I3 concentric with said bore, said bore and counterbore being normal to the inclined top face of said holder. The bore I2 is in registry with a bore 14 that extends through the arm 35 and a boss 35a on the under side thereof. Swiveled in bores I2, I4 is a tubular sleeve I5 having a flanged upper end portion seating in counterbore I3. On that portion of the sleeve that projects below arm 35 is a friction washer I6, and five-arm star-wheel 71 that is urged against said friction washer by a pair of lock nuts I8, I8 threaded onto the lower end portion of said sleeve. One or more setscrews 19 may be provided for securing the star wheel to the sleeve so that rotation of the star wheel will rotate the sleeve. Projecting upwardly from the top flange of sleeve 15 is a pair of spaced studs 80, that flt into complemental recesses formed in the bottom face of a. work-supporting plate 8| that rests upon the top face of holder II. The top face of the supporting plate 8| is formed with a shallow recess 82 having the same profile as the base flange 30a. of the work, and with a countersunk aperture 83 in said recess. which aperture is in registry with the internal bore of sleeve 15.

The arrangement is such that a valve stem 30 may be mounted upon the work seat with its stem portion within the bore of sleeve I5 and its base flange 36a. seated in recess 82, bottom face uppermost. The recess 82 is somewhat shallower than the base flange 3611 sothat the latter projects slightly above the top face of supporting plate 8i, as is clearly shown in the drawings. To protect the leading end of the valve stem flange during the bufling operation, suitable guard means is provided. To this end a rigid metal support 85 is secured to the under side of holder II at the leading end thereof, and projects forwardly therefrom, and to the free end of said support is secured an angular, rearwardly extending, flexible metal guard plate 00. Said plate 80 normally is disposed at an angle above the forward end of plate M and the work thereon, as shown in broken lines in Figure 7, which permits the work easily to be mounted in the work support. When the latter passes the buffing mechanism presently to be described, the plate 88 is flexed thereby and forced onto the 1 1 work, as shown in full lines in Figure '7. The

trailing end of the guard plate 80 is notched as shown so as better to conform to the contour of the work.

In order that the work may be presented in proper angular position to the respective bufiing mechanisms and to the work-ejecting mechanism, means is provided at three different regions of the orbit of the work for angularly turning the work-supporting plate 83 relatively of the holder II, which turning is effected by mechanism that engages the star wheel H. The first turning of the work, in its second passage through the machine, is effected at about 60 beyond the loading station A, at which point the work is turned whereby the long axis of its base flange 30a is changed from a radial position with relation to the turret to a position that is transverse thereto. This work-turning mechanism is best shown in Figure 3 to which attention is directed.

Mounted upon the top plate I? is an upstanding Cshaped bracket 80 in the top of which is a slot 89 disposed radially of the turret 22, and mounted in said slot is an upstanding stud 00 that extends into the orbit of the star wheels H in position to be engaged by one of the arms thereof. The arrangement is such that the star wheels, in passing the stud 90, are turned angularly 90 thereby, with the result that the worksupporting plate BI and work 36 thereon are correspondingly turned from the position shown. in full lines in Figure 3 to the broken line position therein. The stud 00 is adjustable in slot 89 to assure accurate angular turning of the star wheel.

The second turning point of the work, in its second passage through the machine, is effected at a point substantially from the loading station A, at which point the work is turned 180. The trailing end of the work is buifed, by apparatus presently to be described, before said Work reaches the second turning point, so that in passing said turning point the position of the work is reversed and its buffed, trailing end becomes the leading end therebeyond. The second work'- turning mechanism is best shown in Figure 9 to which attention now is directed.

Mounted upon the top plate 57 is an. elongated, arcuate, upstanding bracket 02 that is disposed concentric to the turret 2'2, and has its top formed with three slots 03', 93 disposed radially of said turret. Mounted in each slot 93 is an upstanding stud that is adjustably' positionable radially of the turret, said studs being designated 94', 9.5 and 06 respectively. The studs 04, 95 and 96 extend into the orbit of the star wheels TI, each I of which engages said studs in succession in the order named, and is turned thereby through 180 as will be apparent from a comparison of the full line and dotted line positions or" the star wheel and the work in Figure 9.

The third turning of the work in its second passage through the machine, is effected after the work has traveled substantially 290 past the work-loading station A. At the third turning the work is moved angularly 90 so as again to move its long axis into a position that is radial with relation to the turret 22. In this latter position, only a relatively small portion of the base flange 30a of the work is overlaid by the guard plate 86, so that automatic ejection of the finished work easily is accomplished, as presently will be explained, and the work-supporting plate 80 is properly positioned to facilitate the mounting of new work thereon.

As is most clearly shown in Figure 10, the aforementioned third turning of the work is effected by means of an upstanding bracket 98 that is mounted upon top plate II, the top of said bracket being provided with a holder 99 for a flat, flexible, metal arm I00. the free end of which projects into the orbit. of the star wheels TI. The arm I00 is adapted to engage an arm of a passing star wheel and turn the latter and the work angularly 90, from the position shown in full lines in Figure 10 to the position shown in broken lines therein.

The first buffing of the bottom face'of base flange 35a of the work is effected at a point beyond the loading station A, and is accomplished by a wire bristle brush I02 that rotates upon a horizontal axis, and beneath which the work is moved, as shown in Figure '7. The brush I02 is mounted upon one end of the shaft of-a-n electric motor I03, and the latter is mounted upon a shelf-like slide I04 that is carried by and vertically adjustable upon a bracket I055 mounted upon top plate H. The vertical adjustment of the slide I04 permits the motor I03 to be repositioned to compensate for Wear of the brush I02. The brush I02 rotates in a direction that is opposite to the orbital movement of the work when the brush engages the latter, and the downward inclination of the work in the direction of its leading end makes it possible to cause the brush to engage the work medially thereof, preferably at a point slightly forward of its short axis, with the result that excessive wear on the guard plate is obviated and scuiflng of the small, unguarded portion of the leading edge of the work is avoided.

The above-described b-uflilng mechanism is positioned immediately anterior to the mechanism that turns the work angularly through 180. The mechanism for effecting the second bufling operation on the bottom of the base flange of the work is positioned immediately posterior to the aforementioned work-turning mechanism. Said mechanism is identical with the bufling mechanism just described, and is designated by the same reference numerals with the exponent a. It buffs that portion of the work that was at the leading end of the latter during the previous bufling operation.

The finished work is ejected from the apparatus at a point 36 removed from the loading station A, at which point the work is subjected to an upwardly directed blast of air that lifts it off its seat on supporting plate SI and projects it into the open mouth of a downwardly inclined chute I06 that is open at its lower end. The chute is formed with an arcuate neck portion "16a adjacent its mouth for deflecting the upwardly projected work laterally so that it falls into the inclined portion of the chute rather than back through the mouth thereof. A suitable receptacle (not shown) may be positioned beneath the delivery end of the chute to receive the work.

The blast of air that ejects the work reaches the latter through the lower end of the tubular sleeve I5 of the inner work seat. The air blast comes from an upwardly directed nozzle I I I that is positioned directly below the orbit of said work seats, means being provided for periodically releasing the air as successive work seats are in vertical alignment with said nozzle.

To this end a diaphragm valve I08, Figure 2, is mounted upon top plate I! and connected with an inlet pipe I89 extending to a suitable source of pressure fluid (not shown). A flexible outlet pipe IIU extends from said diaphragm valve to the upwardly directed nozzle I I I, the latter being supported by a suitable bracket H2. Operation of the diaphragm valve is effected by means of a control valve II 3 that is connected through pipe I I4 with said diaphragm valve and connected by pipe I I5 with a suitable source of pressure fluid (not shown). Operation of control valve H3 is effected by means of a pivotally mounted lever IIG that has a cam roller II'I journaled in its free end, which cam roller extends into the orbit of a circumferential series of cams IIS, IIS mounted upon the under side of the gear 2i. There are the same number of cams as there are arms 35, and said cams are so positioned as to engage the cam roller II? to depress lever IIB at the same instant an inner valve seat is directly over nozzle IIl, whereby a blast of air is directed against the work to eject the same as described.

If desired, a table or platform I20 may be con structed beside the front of the machine for supporting a supply of the work to be treated in the machine.

The apparatus is substantially automatic in operation since it requires the services of but one operator, who sits at station A and removes the work from the outermost work seats and places the same on the innermost Work seats, and then places an untreated work-unit on said outermost work seat. The invention saves time and labor in the manufacture of rubber valve stems, and achieves the other objects set out in the foregoing statement of objects.

The modified structure shown in Figure 11 is an inner work seat that is identical with those previously described except that it has a worksupporting plate am that is somewhat smaller than the plate 8| previously described, and has a work-receiving recess in its top face that is circular instead of an elongated or rhombus shape, being thus adapted to receive a valve stem I22 having a circular base flange as shown. The apparatus is capable of buffing the valve stems I22 with the same facility that it buffs the valve stems 36, the arrangement being such that the machine can be altered to operate upon the different types of work simply by transposing the supporting plates 8| or 8| a.

Other modification may be resorted to without departing from the spirit of the invention or the scope of the appended claims, which are not limited wholly to the specific construction shown or exact procedure described.

What is claimed is:

1. The method of buffing valve stem base flanges which comprises bufling a portion of the base flange thereof toward its margin, partly rotating the valve stem on its axis, and thereafter bufling another portion of the base flange toward its margin.

2. The method of buiflng valve stem base flanges which comprises feeding a valve stem in a course lying in a single plane with the said base flange disposed at an angle to said plane, and abrading the base flange from the medial region thereof toward its trailing edge as it is so fed.

3. The method of bufling valve stem base flanges which comprises feeding a valve stem in a horizontal plane with the leading edge of said base flange downwardly inclined with relation to said plane, abrading the uppermost region of said base flange as it is so fed, rotating the valve stem on its axis through 180, and thereafter abrading the uppermost region of said base flange as it continues to be fed.

4. The method of abrading flexible valve stem base flanges which comprises feeding a valve stem in a plane with the base flange thereof disposed perpendicular to said plane, and without lateral support, abrading the leading face of said base flange oppositely of the movement of the valve stem in its course, whereby the base flange is flexed rearwardly, and rigidly supporting said base flange after it is so flexed and while the abrading thereof continues.

5. The method of abrading flexible valve stem base flanges which comprises feeding a valve stem in the general direction of the axis of the stem with the base flange at the leading end thereof, and without lateral support, abrading the leading face of said base flange at each side of the medial region thereof whereby the base flange is flexed rearwardly and the abrading progresses toward the trailing edges thereof, then turning the valve stem angularly through 90", and then repeating the abrading operation as described.

6. In apparatus for buffing valve stem flanges, the combination of a rotary abrading device, a

valve-stem-supporting structure movable relatlvely thereof and so constructed and arranged as to carry the base flange of the valve stem substantially edgewise to tangential engagement with said abrading device, and a guard on said supporting structure overlying the leading portion of said base flange.

'7. In apparatus for buffing valve stem flanges, the combination of a rotary abrading-device, a valve-stem-supporting structure movable relatively thereof and so constructed and arranged as to carry the base flange of the valve stem substantially edgewise to tangential engagement with said abrading device, and a yielding guard on said supporting structure overlying the leading portion of said base flange, said guard normally standing away from said base flange to facilitate mounting of the valve stem on said support, and being flexed into engagement with the leading portion of the base flange by engagement with said abrading device.

8. A combination as defined in claim 7 in which the valve-stem-support is angularly disposed so as to present only the trailing portion of the valve stem flange to the. abrading device.

9. In apparatus for buiflng valve stem base flanges, the combination of a support for a valve stem, the upper face of said support being inclined whereby it holds the base flange of said stem in tilted position with relation to the horizontal, means for moving said support in a continuous course in a horizontal plane, abrading means positioned at spaced points along said course, each of said means being positioned in the path of the trailing portion only of the base flange of said valve stem, and means intermediate said abrading means for turning the valve stem angularly on its own axis through 180.

10. In apparatus for buffing valve stem base flanges, the combination of a support for a valve stem, means for moving said support in a continuous course, rotary abrading means extending into the path of the base flange of the valve stem at a plurality of points in its course, means for turning the valve stem angularly between abrading units so as topresent different portions of its base flange to successive abrading units, and means controlled by the movement of said support for ejecting the valve stem from said support.

11. In apparatus for bufling the base flanges of rubber valve stems, the combination of a pair 1 of abrading wheels rotating in opposite directions between parallel planes, a work support formed with a rounded nose and work-supporting faces receding therefrom, and comprising a spindle projecting from said nose upon which a valve stem may be mounted, and means for moving said work support between said abrading wheels, in a direction opposite to the movement of the adjacent faces thereof, the latter being in such proximity as to flex the base flange of the valve stem rearwardly onto the work-supporting faces of said support.

12. In apparatus for bufling the base flanges of rubber valve stems, the combination of a pair of spaced apart abrading mechanisms each comprising a pair of abrading wheels rotating in opposite directions between parallel planes, a work support comprising a spindle adapted to support a valve stem by engagement in the axial bore thereof, means for moving the work support in the general direction of the axis of said spindle in a course which carries the valve stem, in succession between the abrading wheels of the respective abrading mechanisms whereby the base flange of the valve stems is completely buffed on its forwardly facing side, and means for angularly turning said spindle on its axis and retaining it in turned position while passing the second abrading mechanism.

13. In apparatus for bufflng the base flanges of rubber valve stems, the combination of a Work support comprising a spindle adapted to support a valve stem by engagement in the axial bore thereof, and means for turning said spindle on its axis through an angle of 90", means for moving said work support in a continuous course, rotary abrading mechanisms so positioned at spaced points along the course of the work support as to abrade the base flange of the valve stem carried thereby, and means in the course of the work support to operate the spindle-' turning means while the work is in engagement with one of said abrading mechanisms.

HORACE D. STEVENS. 

